diff options
| author | Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> | 2019-06-14 09:11:41 -0400 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2019-06-17 11:52:47 +0100 |
| commit | 8f5c9037a55b22e847f636f9a39fa98fe67923d1 (patch) | |
| tree | ec49aafa76c82ea1548fabdea1e4f10176c7313c /arch/arm64 | |
| parent | 1a2a66db4967d66402501c43bdfe9d68be54f648 (diff) | |
| download | linux-8f5c9037a55b22e847f636f9a39fa98fe67923d1.tar.gz linux-8f5c9037a55b22e847f636f9a39fa98fe67923d1.tar.bz2 linux-8f5c9037a55b22e847f636f9a39fa98fe67923d1.zip | |
arm64/mm: Correct the cache line size warning with non coherent device
If the cache line size is greater than ARCH_DMA_MINALIGN (128),
the warning shows and it's tainted as TAINT_CPU_OUT_OF_SPEC.
However, it's not good because as discussed in the thread [1], the cpu
cache line size will be problem only on non-coherent devices.
Since the coherent flag is already introduced to struct device,
show the warning only if the device is non-coherent device and
ARCH_DMA_MINALIGN is smaller than the cpu cache size.
[1] https://lore.kernel.org/linux-arm-kernel/20180514145703.celnlobzn3uh5tc2@localhost/
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Tested-by: Zhang Lei <zhang.lei@jp.fujitsu.com>
[catalin.marinas@arm.com: removed 'if' block for WARN_TAINT]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/cache.h | 7 | ||||
| -rw-r--r-- | arch/arm64/kernel/cacheinfo.c | 4 | ||||
| -rw-r--r-- | arch/arm64/mm/dma-mapping.c | 12 |
3 files changed, 16 insertions, 7 deletions
diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h index 758af6340314..d24b7c1ecd9b 100644 --- a/arch/arm64/include/asm/cache.h +++ b/arch/arm64/include/asm/cache.h @@ -91,6 +91,13 @@ static inline u32 cache_type_cwg(void) #define __read_mostly __attribute__((__section__(".data..read_mostly"))) +static inline int cache_line_size_of_cpu(void) +{ + u32 cwg = cache_type_cwg(); + + return cwg ? 4 << cwg : ARCH_DMA_MINALIGN; +} + int cache_line_size(void); /* diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c index 0c0cd4d26b87..969fcc3be556 100644 --- a/arch/arm64/kernel/cacheinfo.c +++ b/arch/arm64/kernel/cacheinfo.c @@ -30,12 +30,10 @@ int cache_line_size(void) { - u32 cwg = cache_type_cwg(); - if (coherency_max_size != 0) return coherency_max_size; - return cwg ? 4 << cwg : ARCH_DMA_MINALIGN; + return cache_line_size_of_cpu(); } EXPORT_SYMBOL_GPL(cache_line_size); diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 674860e3e478..ff410195dc1c 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -91,10 +91,6 @@ static int __swiotlb_mmap_pfn(struct vm_area_struct *vma, static int __init arm64_dma_init(void) { - WARN_TAINT(ARCH_DMA_MINALIGN < cache_line_size(), - TAINT_CPU_OUT_OF_SPEC, - "ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)", - ARCH_DMA_MINALIGN, cache_line_size()); return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC)); } arch_initcall(arm64_dma_init); @@ -472,6 +468,14 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, const struct iommu_ops *iommu, bool coherent) { + int cls = cache_line_size_of_cpu(); + + WARN_TAINT(!coherent && cls > ARCH_DMA_MINALIGN, + TAINT_CPU_OUT_OF_SPEC, + "%s %s: ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)", + dev_driver_string(dev), dev_name(dev), + ARCH_DMA_MINALIGN, cls); + dev->dma_coherent = coherent; __iommu_setup_dma_ops(dev, dma_base, size, iommu); |